The original fishworks team were the first to a create hybrid storage appliance. Jump ahead a decade later to find that ZFSSA was the very last to market in all flash. It shouldn't be a complete surprise that it's being replaced in the cloud.
Don't point fingers at FS1, although I'm sure some nasty politics were played here. Instead, look right at ZFS management. They've spent the last 7 years since the acquisition flying business class around the world, pretending to glad hand customers as they rack up their miles and status. The product line must spend close to 1 million a year in travel alone. And for what? What's fundamentally changed with the product since 2010?
I'd argue the product has already been in sustaining mode for a very long time. And aside from the new SVP, it's been that same core team the whole time. It's a shame that guy wasn't hired sooner.